ABSTRACT This application is in response to NOT-GM-20-013 Notice of Special Interest (NOSI), Availability of Administrative Supplements for Equipment Purchases for NIGMS Awardees for the parent grant 1R01 GM136874-01 entitled ?Regenerative Lipid Mediators for the Management of Severe Burn Wounds.? In this parent grant, we need to determine and optimize the sustained release of regenerative lipid mediators (ReLiMs) from ReLiM loaded amino acid-based poly(ester amide) (AA-PEA) hydrogels (Agels) in Aim 1 and from constructs that integrate adipose-tissue derived microvascular fragments (MVFs), ReLiMs, and Agel in Aim 2 with the overall goal of optimal healing of burn wounds. Since the submission of the parent project, samples requiring analysis by the current mass spectrometry (MS) instrumentation in our center?s Lipidomics Core has markedly increased due to the increased research activities on lipids. Consequently, the samples for this parent grant now greatly exceed the MS capacity of the Core. Moreover, we recently found that ReLiMs are bioactive even at an unexpectedly low dose below the detection limit of the Core instruments. This means the period for releasing bioactive ReLiM levels from optimal Agel dressings should be much longer than that originally expected in the parent project, and we could avoid the Agel replacement on wounds and associated complications. Thus, measuring time courses of ReLiM release from various Agels at low but bioactive doses is vital. The ultra-high sensitive and fast hybrid triple quad-ion trap (QTRAP) 6500+MS is fully capable of such measurement. Currently, no facility within a few hours? drive has a QTRAP6500+MS system, so we have no ready access to this equipment. Outsourcing our samples is also not reliable, time-effective, or affordable due to their huge number and complexity. We have to conduct the time-consuming development of the LC- QTRAP6500+ analysis methods tailored for each type of ReLiM-Agel and ReLiM-MvF-Agel. The maximum funding provided by this supplement will be sufficient to purchase the MS part of the LC-QTRAP6500+MS system, which is critical for successful implementation of the parent project. Our center will provide the remaining components: an HPLC, a UV(/VIS) detector, and an autosampler compatible with the QTRAP6500+ MS, to form an autosampler-LC-UV-QTRAP6500+MS system sufficient to meet the updated analytical needs of the parent project. The PI?s group has nearly two decades of strong expertise and hands-on operating experience with LC-UV-MS/MS, thus will be able to quickly set up, maintain, and adjust the LC-UV- QTRAP6500+MS system for the various methodologies and conditions optimal for the parent grant. In summary, the purchase of the proposed QTRAP6500+ MS is vital for the ReLiM analyses proposed in the parent grant. The pharmacokinetic data, including low but bioactive doses, acquired with the QTRAP6500+MS provided by this grant will enable the PI?s group to develop the ReLiM-functionalized dressings, with no or minimized graft-donor needs, capable of even better healing than was originally expected in the parent project.